PNVIBA接枝聚苯乙烯微球制备与颗粒直径控制

通过使聚N-乙烯基异丁酰胺(PNVIBA)大分子单体与苯乙烯在乙醇/水的混合溶剂中进行自由基分散共聚反应,得到热敏性PNVIBA接枝聚苯乙烯(PNVIBA-g-PSt)高分子微球。用投射电子显微镜对微球的形态进行观察,同时考察PNVIBA起始浓度、苯乙烯浓度、引发剂浓度、聚合反应温度和混合溶剂中水的体积分数对微球直径的影响。实验结果表明,在较宽的聚合反应条件下,得到的接枝高分子颗粒均保持球形并具有很好的单分散性,接枝高分子微球的数均直径与反应条件的关系遵循Dn=KPNVIBA]-0 39St]0 80I]-0 14;微球直径随聚合温度的升高和混合溶剂中水含量增加而降低。

Study on Preparation and Particle Size Control of Poly(N-Vinylisobutyramide) Grafted Polystyrene Microspheres

Poly( N -vinylisobutyramide) grafted polystyrene (PNVIBA-g-PSt) microspheres were prepared by dispersion copolymerization of PNVIBA macromonomer with styrene in ethanol or ethanol/water mixed solvents. The reaction parameters such as PNVIBA macromonomer concentration ,styrene concentration ,initiator concentration ,polymerization temperature and the percentage of water in the ethanol/water mixed solvents can affect the final diameter of the PNVIBA-g-PSt microspheres.The particle size in diameter ( D n) follows the relationship D n= K -0 39 0 80 -0 14 ,and decrease with increasing polymerization temperature and percentage of water in mixed solvents.The particle size of the PNVIBA-g-PSt microspheres can be controlled in sub-micron range by varying the reaction conditions.